This invention relates generally to computing systems and more specifically relates to the control of cooling systems in computing systems, especially but not limited to, fans used to maintain electronic components within an acceptable operating temperature range.
Computing systems utilize a plurality of electronic components including integrated circuits that generate a substantial amount of heat during operation. Cooling systems of various types are employed to maintain the temperature of the electronic components and the environment of the electronic components within an acceptable operating temperature range. For example, a personal computer in a desk-top case typically utilizes one or more fans mounted at the rear of the case to circulate outside air through the case to carry away heat generated by integrated circuits, especially the primary microprocessor, and other electronic components contained within the case.
The control of the speed of such cooling fans may be fixed or varied in steps under the control of a hardware management-driven device. In a basic implementation, the fan speed is not regulated and runs at its revolutions per minute (RPM) rating associated with a nominal applied operating voltage/current that is not varied. A hardware management control device, such as a baseboard management controller (BMC), can provide a low-level control and sensing of the speed of the fans and of operating temperatures of key components. Such a control device operates independent of the operating system (OS) used by the computing system and is active even prior to the loading of the operating system. Some basic input/output systems (BIOS) operate in conjunction with the BMC and provide some level of user control by setting BIOS parameters, such as setting a user alarm to be issued when a predetermined operating temperature of the primary microprocessor is exceeded.
Such uses and functions give rise to needs that are discussed at the beginning of the Detailed Description section in view of the implementations of the present invention.